Games are played by wearing a head-mounted display, connected to a game console, on the head, watching a screen displayed on the head-mounted display, and manipulating a controller or other device. With an ordinary stationary display, a user's field-of-view range spreads outside the display screen, possibly making it impossible to focus one's attention on the display screen or resulting in insufficient sense of immersion. In that respect, when a head-mounted display is worn, a user cannot see anything other than an image appearing on the head-mounted display, thereby increasing a sense of immersion into the image world and further enhancing the entertaining nature of the game.